Earthship aquaponics plan

[keith_r]

i've seen a few people use tanks that were quite tall and buried, but they don't allow the fish much swimming room imho.. but the only reason you need surface area is for oxygen transfer.. if you can pump air down 8', that wouldn't be a concern
the other problem with a "deep" tank would be that you could get a "thermocline", and in a water turnover, your temp could swing drastically and cause stress/fish deaths.. i don't think you'd have that problem with an 8' deep tank though
be kinda hard to catch the fish without a good net system too

[2600knurd]

I have only one other thing to add about the depth (from the engineers reading this)about deep versus wide.

If you are looking to keep a large amount of water, it is cheaper to build a 2' high tank that is 8' wide than it is to build an 8' high tank that is 2' wide. The reason being the amount of pressure 8' of water has, you would need an in-ground tank or some serious structural reinforcement.

Example: Take a hypothetical ridiculously-size aquarium that holds 76 MILLION Gallons of water.

Option 1: 3280 feet (over half a mile) square by 1 foot high (so 3280 x 3280 x 1)

The glass thickness would need to be about 0.2 inches! LESS than a quarter inch.

Option 2: 820 feet by 1641 feet by 8 feet high (820 x 1641 x 8)

The glass thickness would need to be about 4.1 inches!

Now, I know what you are thinking: "But I don't have 76 MILLION gallons. I only have 1,000 gallons."

Option 3: 1 foot by 1 foot by 8 feet = (~56 gallons)
Thickness required about 2"

Option 4: 4'6" x 4' x 8' =~1000 gallons
Thickness required about 2"

These calculation are for glass. But the concept of needing more strength for deeper water remains no matter what material you use. In-ground tanks will be best.

In summary, my 76M gallons from my Option 1: (over 300 Ml -- That's MEGALITRES) requires walls with a strength of X.
My Option 4, 1000 gallons (~4 kl -- kilolitres), requires walls with a strength of 260X (260 TIMES the strength) to hold 1/76,000th (0.001%) the amount of water.

Enjoy the thought experiment!

[badflash]

This is all conjecture as far as how deep vs. how wide. It would also have a lot to do with the type of fish you choose. I have very successfull rearing in 100 gallon stock tanks, and 20 gallon aquariums, 55, 90 and 110. All my systems have been close to 1:1. Tilapia send to spend their time close to the bottom, so the water above them would be mostly wasted.

I'd need to see some studies before I would go for any one design.
Tanks 8' into the ground would have a lot of thermal moderation. Aeration at the bottom would keep the temperature pretty even. 2' tanks don't give a lot of swimming room though.